New Advances in Cervical Spine Surgery Microendoscopic Decompression of the Cervical Spine Microendoscopic decompression of the posterior cervical spine is a minimally invasive surgical procedure performed with the aid of a tubular approach as well as an endoscope or microscope. Its purpose is to reduce muscle damage due to traditional surgical access. This surgical technique requires rigorous training and a steep learning curve. In contrast, its surgical indications are essentially the same as those for conventional posterior cervical open decompression, including postero-lateral cervical disc herniation as well as foraminal stenosis. The outcomes at 1 year postoperatively are similar to those of conventional laminectomy and anterior discectomy and fusion with bone graft. The incidence of dural sac injury ranges from 1-4%, which is slightly higher than that of conventional laminectomy. Since minimally invasive laminectomy has not yet shown significant advantages, its clinical value needs to be confirmed by further studies. The AO Spinal Cord Study The North American AO Spine Society conducted a multicenter observational study of 264 patients with spinal cord cervical disease. In addition, the study included an additional 366 international patients separately. Two-thirds of these patients underwent anterior cervical spine surgery, while the other third underwent posterior surgery. After a weighted average of the patient bases, clinical outcomes were significantly improved in both groups compared to the preoperative period, while there were no significant differences between the two groups. In the North American portion of the study population, factors associated with clinical outcomes were age, severity, smoking status, gait abnormalities, comorbid psychological disorders, and pre-treatment spinal cord cross-sectional area. In the international patient population, the average age of patients from Asia and Latin America was lower than that of North American patients, and ossification of the posterior longitudinal ligament of the cervical spine was more common in the Asian patient population. Furthermore, there is no correlation between patient psychological disorders and clinical outcomes. Complications are associated with advanced age, co-morbidities such as obesity, diabetes or gastrointestinal dysfunction, and staged or complex surgical procedures. Cervical fusion To clarify the best way to determine cervical fusion in terms of imaging, the Cervical Spine Research Society conducted a systematic literature review study. The best preferred method of determination was to measure the distance between the tips of adjacent spinous processes on lateral cervical spine films and compare the change in this distance in hyperextension and hyperflexion of the cervical spine. Cervical fusion is considered to be achieved if the change in spinous process tip distance in the powered position is less than 1 mm. If further evaluation is necessary, a CT scan is recommended. Complications Dysphagia is the most common long term complication after anterior cervical fusion. The application of fludrocortisone or, more recently, gelatin sponges impregnated with methylprednisolone (Depo-Medrol) placed in the retropharyngeal space can significantly reduce the incidence of dysphagia. So far, although this method has not been reported to affect fusion or cause esophageal perforation, its possible side effects remain to be further demonstrated. Other methods to reduce the incidence of dysphagia include: preoperative instruction of the patient in tracheal and esophageal nudging, reduction of intraoperative esophageal traction time, avoidance of bone induction protein (BMP), use of low-cut or smoother anterior cervical plates, and reduction of pressure on the endotracheal tube. Moreover, the incidence of postoperative swallowing distress is also associated with preoperative patient psychological factors. The National Surgical Quality Improvement Research Program (NSQIP), is a quality improvement program that can be used to identify specific postoperative complications and their associated risk factors. The results of data from this research program show that postoperative incisional infection rates are significantly lower in anterior cervical surgery than in posterior cervical surgery. Risk factors for postoperative incisional infections were: body mass index greater than 35 kg/m2, operative time greater than 3 hours and long-term use of corticosteroid medications. Results of a case-control study of intra-incisional vancomycin use showed a reduction in postoperative incisional infection rates of approximately 63% to 89% in the use group compared to the control group. However, the findings of this study need to be further confirmed due to the influence of confounding factors.